Chemical Compositions of Essential Oils and Antimicrobial Activity of Elettariopsis triloba from Vietnam

Abstract

The herb, Elettariopsis triloba (Gagnep.) Loes. (syn. Amomum trilobum Gagnep. or Elettariopsis trilobum (Gagnep.), has been used ethnomedically for the treatment of rabies, inflammation and amelioration of microbial infections. We report herein the chemical constituents and antimicrobial activity of the rhizome essential oil of E. triloba from north-central Vietnam. The technique of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) was used to analyze the oil sample while the microdilution assay was employed to determine the antimicrobial efficacy. Monoterpene compounds including camphene (23.2 %), fenchyl acetate (12.7 %), bornyl acetate (10.6 %), α-pinene (5.7 %) and limonene (5.1 %) were the main constituents of the rhizome essential oil. The essential oil displayed antimicrobial activity only towards Gram-positive bacteria of Enterococcus faecalis ATCC 299212, Staphylococcus aureus ATCC 25923 and Bacillus cereus ATCC 14579 with minimum inhibitory concentration (MIC) values of 16.0 μg/mL, 256 μg/mL and 32.0 μg/mL, respectively. The oil also inhibited the growth of the yeast, Candida albicans ATCC 10231, with a MIC value of 16.0 μg/mL. The chemical constituents and antimicrobial activity of essential oil from E. triolba were being reported for the first time and validation of the ethnomedicinal usage of the plant.